A process during early
embryonic development in
animals in which large-scale
cell migration occurs and different cell types emerge to form the
germ layers (
endoderm,
ectoderm, and sometimes
mesoderm). The stage takes place just after the
blastula stage and begins with an
invagination (indenting) of the hollow ball of
cells. During this process, the
embryo is called a
gastrula.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.